Sign in with
Sign up | Sign in
Your question

Can I power 2 fans with one MB header?

Last response: in Motherboards
Share
March 4, 2007 4:47:53 PM

I've put up with a REEEAAALLLLY loud PC for over 2 years now :cry:  , and it's time to quiet the beast. I don't need it silent, just quieter. I'm about to get a fan controller and some variable fans throughout. My question is, if I replace the 2 80mm fans on my Thermaltake Tower 112 with some variable ones, can I power them both from the CPU fan header, or would that be too much of a load? If it can be done, how should I wire them up? It has been unused since new, but I would like to be able to use the Cool n' Quiet feature. Or am I just going to have to use the fan controller for them also?

More about : power fans header

a c 124 V Motherboard
March 4, 2007 5:58:19 PM

That will vary from board to board....its not worth blowing the fan header trying it....You would have to know how much power each fan draws.....if the board could handle it....then you have to just make a splitter and run then in parallel.

so

+ ------------+fan1 RED
|________+fan2 RED

- ------------- - fan1 BLACK
|_________ -fan2 BLACK

speed----------fan 1 YELLOW dont connect this to the other fan

i ran a 80 and 92 on q-fan(from 1 fan header) this way......

Now for running a speed controlled fan on a fan controller....thats not good...the speed controlled fan used 12 volts and based on temperature changes its speed....so once your board starts feeding it 7 volts things start to not work.....lets not forget new boards feel fans with PWM....who knows what that does to a speed controlled fan....

so what do you do.....use one or the other.....

I recommend getting 2 normal fans since they will spin @ the same speed on the same voltage....self controlled fans use temp....and will spin at a different rate....your heat sink is made for a push pull setup.....the same speed on each side is good

if you are sure your board can handle 2 fans....then get them hocked up and away you go....if not grab one of those Zalman fan mates....and get a 3 to 4 pin adapter to run the fans off a hard drive power cable...and most 2 to 4 pin adapters still have a cable to run to the board so you can see fan speed.....
a b V Motherboard
March 4, 2007 6:02:32 PM

Quote:
can I power them both from the CPU fan header


Of course you can!

But you'll destroy your M/B!

That fan header is not designed for 2 fans and a variable resistor, it will never handle the load, look for other alternatives.
Related resources
March 4, 2007 7:00:32 PM

Quote:
I recommend getting 2 normal fans since they will spin @ the same speed on the same voltage....self controlled fans use temp....and will spin at a different rate....your heat sink is made for a push pull setup.....the same speed on each side is good




So normal fans work with a fan controller? I was under the impression they had to be variable, but variable just means they have their own temp sensor, right? Do you know of any good automatic fan controllers that will power lots of fans, with multiple fans on the same function? Like controlling all the front fans at the same time (up to 4 maybe), or both CPU fans at once. I have two 5.25" bays left and don't mind using them both if I need to. I checked out some Aerocool controllers, but people generally didn't give great reviews on Newegg, and the same with the Thermaltake Hardcano.
a c 124 V Motherboard
March 4, 2007 8:24:38 PM

I do not know of any good automatic ones...

as for fans....most computer fans will run down to about 5 volts.....some small fans..40mm ones will not start on 5volts....but most 80+ will......

i was running a zm-mfc1 but it is manual....i just used to to turn down my Sonata fans... and to cut my cpu fan to 11volts....that will run almost any 2 80mm fans....well not Vantec tornadoes....

Just to clear things up.....does your board auto control the fan speed? if so...maybe you can run on on cpu and one on system(front bottom on ure board...) then see if it controls them both that way....then run your case fans on your power supply with 3 to 4 pin adapters....

if you want to do it on the cheap...just get them both connected to a Zalman Fanmate and connect it to a 3 to 4 pin adapter....the adjust it to where u want it.....run some stress tests....if the temps are good....keep it that way....if not...turn it up a bit....this way both fans will run the same speed....

Also...there are Antec Tri-Cool fans that have a switch for 3 speeds.....then u can balance noise and performance...

Post back with any questions....also some info on your case would help....how many fans...how fast...how they are connected....


this never hurt my board....but the fans and board play a large role in this....
March 4, 2007 9:30:02 PM

Quote:
Just to clear things up.....does your board auto control the fan speed?


Yes it can, but it's turned off in the bios right now.

Quote:
....also some info on your case would help....how many fans...how fast...how they are connected....




Does this help any? Old pics from when it was new, but all the fans are just cheap ones with straight through 4 pin connectors, and they're all just connected in series on the same HDD connector. There's 4 up front, 2 in back (not including PSU, which I wouldn't want to slow down anyway), and 2 on the tower. Maybe it's overkill, but I've had two hot running HDD's quit and my air cooled WD 40G has been running for about 7yrs straight. Now there's 4 in there, and it runs 24/7. Those are the only fans I'm looking to slow down. I'm thinking I'll just try and run them all off a controller, even if I have to divide the front 4 on separate channels. As long as I can run at least 2 per channel I should be fine. Running them off the MB isn't that big of a deal but I was curious if it was possible.

Do you know how a person might go about attaching a thermistor to a CPU? I wouldn't think I should just go and slide one under the heatsink.

Oh, and my CPU idles at a cool 27c oc'ed to 2.2 and the highest I've ever seen was 41c.
March 5, 2007 6:00:21 PM

I guess MyPhotoAlbum doesn't like me linking to my pics.
a c 124 V Motherboard
March 7, 2007 5:55:04 PM

if you want to post a picture....do it at

http://imageshack.us

or

tinypic.com works well too....

4 fans up front...wow....thats gotta be loud.....and cool....are they all 80's.....

i can not tell you whats the best fan controller as it changed for every user...

I would assume you could use a MFC-1 and run all the front @ 5 volts....

but you can do that without any controller....just wire then to black and red....black and yellow should be what its on now...but make sure they run @ 5 first....do some tests...

i will try to post again when u put a picture.....so i can see what u have.....
!